Eileen B. Fitzpatrick, the senior communication specialist at Freddie Mac, thought she'd have some fun. She took a look at the record high rate since Freddie Mac started its weekly tracking of average rates 39 years ago (the Primary Mortgage Market Survey). That high was 18.63 percent, the week ended Oct. 9, 1981.

Eileen found that for a $200,000 loan at that rate, monthly payments would have been $3,117.17, for annual payments of $37,405.99 and total payments over the 30-year life of the mortgage of $1,122,180 (yes, well above a million dollars).

Compare that with the same $200,000 mortgage at today's rate. Monthly payments would be $1,021.71 for annual payments of $12,260.47 -- and total payments over 30 years of $367,814.

That's a pretty big difference for the same $200,000 mortgage: $2,095.46 less in payments each month, $25,145.52 less in payments each year, and $754,365 less overall.